First Results Emerge from ICESat-2, Satellite Measuring Earth’s Ice Elevation

By Chrysandra Medley

More than a trillion new measurements of the Earth’s surface height are now available to the public as the first results of ICESat-2, a mission devoted to measuring the changing height of Earth’s ice.

Launched last September, the Ice, Cloud, and Land Elevation Satellite-2 carries the Advanced Topographic Laser Altimeter System (ATLAS), an instrument that sends 10,000 laser pulses a second to Earth’s surface.  It measures the height of ice sheets, glaciers, sea ice, and vegetation by calculating the time it takes the pulses to return to the spacecraft.

ICESat-2 is remarkably precise, able to measure ice thickness accurate to the centimeter level.  This helps ice-sheet scientists like Kelly Brunt, ESSIC/CISESS Associate Research Scientist working in the ICESat-2 Project Science Office, mark contributions to mean sea level rise.

“Antarctica is big. It’s larger than the continental United States. So if the surface of the ice sheet lowers, by even a small amount, like say one centimeter, that still means a lot of water is leaving the ice sheet and going right into the ocean,” noted Brunt.

Currently, ICESat-2 is able to determine the surface height of ice sheets to better than 5 CM… and the mission has only just begun.

Launched in September 2018, The long-awaited ICESat-2 mission continues the record of polar height data begun with the first ICESat satellite. ICESat-2 provides far more measurements than its predecessor, adding millions of observations each day to the NSIC Distributed Active Archive Center (DAAC). ICESat took approximately 2 billion measurements in its lifetime, a figure ICESat-2 surpassed within its first week.

With this plethora of new data has come new data products, including ones associated with land ice, sea ice, oceans, vegetation, inland water, and an atmospheric product– but it has also led to discoveries about what else this technology is capable of.

“When the data started coming in, we learned that we can actually map the bottoms of shallow lakes and coastal regions, up to about 20 m in depth,” said Brunt, “Mapping the bottoms of water bodies is what we call bathymetry. And now we need a new data product associated with it! And that’s pretty exciting!”

Other ESSIC scientists heavily involved in the mission include Sinead Farrell, ESSIC/CICS Associate Research Scientist and a member of the ICESat-2 science team, Post-doctoral Associate Adam Greeley, Senior Faculty Specialist Kyle Duncan, and Atmospheric and Oceanic Sciences graduate student Ellen Buckley.

For now, the ICESat-2 scientists are working hard to keep up with the data flow and make small changes to make these early versions of data the best they can be.  With successful results when the mission has only just begun, they’re feeling optimistic.

“Things will only get better!” says Brunt.

To keep up with ICESat-2, follow updates posted on the mission homepage and by @NASA_ICE on Twitter, and look for regular tweets by @KellyMBrunt and @sineadlfarrell.  To keep up with what is happening at ESSIC, be sure to follow our Twitter (@essicumd) and Facebook accounts.